The study also found a reduction in systolic and diastolic blood pressure of about 5 per cent.

Senior author Dr Roberto Fogari said: "This is important because it means that in these patients with elevated blood pressure who were overweight, the blood pressure was not a form of essential hypertension but was hypertension secondary to body weight.

"These findings apply to western societies in general, but only to overweight patients, not to obese patients, with high blood pressure."